Electrically operated continuous steam generator



P 7, 1963 E. E. WILSON 3,104,308

ELECTRICALLY OPERATED CONTINUOUS STEAM GENERATOR Filed Feb. 15, 1960 2Sheets-Sheet 2 Ernest E M'lson IN VEN TOR.

United States Patent 3 164,308 ELEQTRIUALLY GlPERA'IEI) CONTINUOUS STEAMGENERA'IGR Ernest E. Wilson, 12629 Easter; Freeway, Houston, Tex. FiledFeb. 15, 1960, Ser. No. 8,706 6 Claims. (El. HEB-4e) This inventioncomprises a novel and useful electrically operated continuous steamgenerator and more specifically pertains to an apparatus which embodiesthe same basic principles as those set forth in my prior Patent No.2,681,974 of June 22, 1954, but constitutes certain importantimprovements thereover.

The primary purpose of this invention is to improve the water treatingand heating device of my prior patent and to adapt the principlesthereof to a much greater utility in a wider variety of fields ofusefulness.

An important object of this invention is to provide an electricallyoperated steam generating device which shall be capable of readyadaptability to enable it to satisfactorily generate steam from waterwhose mineral content varies widely throughout various localities of thecountry.

A further object of the invention is to provide a device in accordancewith the preceding objects which will enable an easy and very accuratecontrol as to the rate of steam generation by the device.

A further object of the invention is to provide a device in accordancewith the preceding objects which shall be of a construction whichrenders it substantially proof against the detrimental effects ofcorrosion of the water which is boiled therein.

Still another object of the invention is to provide a device inaccordance with the aforementioned objects which shall be readilyadjustable and easily controlled in order to selectively supplytherefrom water at any temperature from that of the supply line to theboiling point; any desired proportion of steam and hot water separatelyor simultaneously; and superheated and dry steam exclusively as desired.

Still another object of the invention is to provide a device in whichthe heating is eflected by electrical means and which readily lendsitself to a considerable variety of electrical connections, differencesof electrical current and the like to eifectively perform its waterheating and/or steam generating functions.

More specifically, it is an important purpose of the invention toprovide a steam generating device as set forth in the preceding objectswherein the rate at which the water is converted into steam by theelectrical means may be controlled by regulating the water level withinthe boiler to thereby vary the area of the electrodes that are immersedin the liquid therein and thus control the heat output of theelectrodes; to vary the spacing of the electrodes from each other tothereby vary the heating effect and also adapt the device to moreelfectively handle waters having different mineral content; and to varyby the electrical input the rate of heating of the water therein.

A further and more specific object of the invention is to provide anelectrically operated steam .generator in compliance with the. abovementioned objects which shall be of a simple, sturdy, long lasting andvery compact and effective construction for the purpose intended.

It is a further specific object of the invention to provide a means formounting and supporting the electrodes and render the same adjustable soas to vary the distance of the electrodes from each other while at thesame time minimizing the tendency of the electrodes to form carbon shortcircuiting paths across their insulators which would therebydetrimentally affect the elficiency and operation of the device.

It is another specific object of the invention to provide an apparatuswhich will enable the steam generated by the Patented Sept. 17, 1963device, after its intended use, to be condensed and then returned intothe 'feed water supply line of the boiler to thereby effect an economyin the operation of the device as well "as eliminate the necessity forseparately disposing of the used steam.

Still another important object of the invention is to pro vide anapparatus in compliance with the hereinbefore set forth objects whereinthe electrodes may be formed as plates, either fiat or curved incross-section and whereby the surfaces of the electrodes will remainparallel to each other under all conditions of their adjustment.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view, parts being broken away and shownin vertical section, showing a suitable embodiment of a continuous steamgenerator in accordance with the principles of this invention;

FIGURE 2 is an enlarged view taken in vertical section substantiallyupon the plane indicated by section line 22 of FIGURE 1 and showing theinternal construction of the boiler of the apparatus;

FIGURE 3 is a horizontal sectional view taken substantially upon theplane indicated by the bnoken section line 3-3 of FIGURE 2 and showingin particular the disposition of the heating electrodes within theboiler chamber of the device;

FIGURE 4 is a horizontal sectional view taken substantially upon theplane indicated by section line 4-4 of FIGURE 2 and showing the lowerend of the boiler chambar, the electrode disposition and the mounting ofthe same in the chamber;

FIGURE 5 is a top plan view of the device of FIG- URE 1; and

FIGURE 6 is a perspective view of the removable closure plate or top ofthe boiler together with the heating electrodes mounted thereon.

In my prior above identified patent there is disclosed a water treatingand heating apparatus which involves the provision of a pair ofstationary electrodes immersed in liquid in a boiler whereby the liquidis heated through the passage of electric current between the electrodesand through the liquid. While this device has proved to be quitesatisfactory for a number of purposes, it has been found desirable toimprove the operation of the same and render the device applicable to agreater variety of different conditions by forming the electrodeassembly adjustable so as to vary the space between the electrodes andthus the length of the path of travel of the heating current through thewater in which the electrodes are immersed. Further, it is desirable toincrease the utility and improve upon the apparatus of my prior patentby rendering the same adaptable to a number of different voltage sourcesof electric current; the providing of different electrical circuitsthrough the device to efiect the heating operation; a control of theliquid level within the device to thereby vary the area of theelectrodes which are immersed in the liquid and thus are eifective forthe heating operation. The present invention provides an apparatus and ameans to eifect the above mentioned desired improvements in theapparatus of my prior patent and to render the principles of theinvention as disclosed in my prior patent capable of application to awider variety of uses.

Referring first to FIGURE 1 for an illustration and understanding of atypical installation in accordance with the principles of thisinvention, there is shown at 10 a steam generator or boiler of aconstruction to be hereinafter set forth to which feed water is suppliedas by a conduit 12 under the operation of a manually operatedfeedreg-ulating valve 14, there being interposed a reservoir tank orchamber as at 16 on the supply side of the'control valve 14. There isfurtherprovided a delivery conduit 13 in the top of the boiler by whichwater. and/ or steam in any desired proportions are delivered by thedevice. Electric current is supplied to the device-in any source as bymeans of conductors shown at 2t while a by-pass line 22 provided with anon-return adjustable pressure check valve assembly 24 is employed toefiectreturn flow from the interior of the boiler into the supplyconduit 12 for a purpose to become subsequently apparent.

Referring now specifically to FIGURE 2 it will be observed that theboiler It} comprises a suitable tank or container which may be providedwith a cylindrical wall 30, an integral bottom wall 32 together with anoutturned flange 34 at its upper end to which is attachably secured asby fastening'bolts 3d a removable plate 38 constituting a cover orclosure to render the boiler airtight. In order to effect a fluid-tightseal between the cover and the interior of the boiler the flange 34 isprovided with a circumferentially extending channel or groove thin itstop surface in which is received a sealing means such as an- O-ring orother packing ring 42. The entire interior of the boiler is providedwith -a corrosion resisting coating or lining of a suitable dielec tricmaterial indicated by the numeral 44'. This liner extends upon thecylindrical interior of the wall 30, and uponthe bottom wall 32' and thecover or closure 38 as shown'in FIGURE 2.. Whilevarious insulatingmaterials 'can'be employed for this liner a quite satisfactory materialis one commercially available and known as Silastic.

The bottom wall 32 of the boiler is provided with a threaded bore intowhich the supply conduit 12 opens, and there is a further threadedopening therethrough indicated at 46 in FIGURE 4.

' As shown'best in FIGURE 3, the closure or cover plate 38-h providedwitha threaded bore or opening 50 with which the delivery line orconduit 18 is connected. The heating operation of this apparatus iseffected by electrical means through a series of electrodes adjustablysupported by the cover 38 and the bottom 32 of the boiler unit ltl: Aswill be best apparentfrorn FIG- URE 2 in conjunction with FIGURESB, 4and 6, each electrode consists of a plate of electrically conductivematerial and preferably one which is corrosion resistant such asstainlesssteel or thelike. In the embodiment illustrated there aredisposed a pair of end'electrodes as at 52 and 54 together with apair-of central electrodes each'designated by the numeral 56; As shownin FIG- URES 3 and 4 these electrodes are preferably spaced andpositioned'so that they will be uniformly spaced from each other and thespace between the electrodes will extend substantially. over the entirecross-sectional area of the interior of the boiler. Each electrode isprovided at its upper and lower end With a projecting axle, the setofupper axles being'indicated by the" numerals 53 while the lower axlesare indicated by the numerals 60. As shown in FIGURE 3, theaxles aredisposed closely adjacent the one edge of the two outer electrodes 52and 54, but more nearly at the center of the two electrodes 56, thearrangement'being such that the four upper axles are disposed'in thesame diametrical line across the boiler, and as shown in FIGURE 4thebottom set of axles 60 are likewise disposed along a diameter of theboiler,

these two diameters lying in the same vertical plane extending centrallyof the boiler. By this arrangement, rotation of the electrodesand theiraxles will result in causing the electrodes tovary their spacing withrespect to each other While their adjacent surfaces will always remainequidistantly spaced from each other. This con dition is true regardlessof whether the electrodes consist of flat'plates of material, or consistof plates having.

various desiredcross-sectional curvatures.

When the electrodes are rotated into their maximum which receives theby-pass conduit 22, this opening being ,ings .for a twofold'purpose.

. 4 p spacing between their adjacent faces, this being the positionshownin FIGURES 3 and 4, it will be observed that the opposite verticaledges of the electrodes will be closely adjacent to the corrosion prooflining 44 of the side wall of the boiler, with the electrodes beinguniformly spaced over the cross-sectional area of the inthe electrodesand therefore the most effective length of passage of the currentthrough the liquid being heated. This variability is necessary since theminer-al content and consequently the electrical conductivity of watersin various localities of the country is subject to wide variation and asingle fixed spacing of the electrodes would not permit the device tooperate with equal efficiency in heating waters of widely varyingmineral C0r1- tent. Therefore, the rotationally adjustable mounting ofthe electrodes enables the same device to be adjusted to operate atmaximum efiiciency with waters of Widely vary ing mineral content. p l

The upper set of axles 58 are rotatably journaled in insulating bushings62 which are of any suitable material, Teflon being found to besatisfactory for this purpose, with the upper ends of the axlesprojecting above these bush- The lower axles so in turn are journaledand supported in suitable sockets or bores 64' provided in a dielectricbody or block 66, the latter inturn having positioning bores 68in itsbottom surface in which are received upstanding positioning dowel pins70 rising from the bottom wall 32. A central opening '72. through thedielectric body is registered with the inlet ofthe supply line 12 tofacilitate inlet of feed water into the boiler. I

By the foregoing construction, it will be seen that the set ofelectrodes is rotatably mounted and journaled in bearing members of adielectric character in theremovable cover plate 38 whereby they maybe'removed with this cover as indicated in FIGURE 6, and at their lowerends are journaled in a dielectric body 66 which likewise can be removedwith the cover plate if desired or may remain attached to the bottomWall of the boiler when the cover and electrode assembly are removed.

The previously mentioned'upwardly extending'and projecting ends of theupper set of axles 58 have secured thereto in any suitable manner forfixed but removable attachment thereto a set of actuating arms or cranks74, see in particular FIGURE 5. The outer ends of these arms arepivotally connected to and embraced by the bifurcated arms 76 of adielectric body '78 whereby the arms of each of the electrodes isconnected together for simultaneous operation by a push and pull motionon the body '78. Further, the previously mentioned electric conductors20 are connected each to one of the upwardly extending portions of theaxles 58, in good electrical contact therewith by means of externalthreads 80 on the axles upon which lock nuts 82 are provided.

At this point it should be observed that the actual means andarrangement by which electric current is supplied to ployed since theinvention lends itself to a wide variety of such arrangements, and sincethe number of electrodes can likewise be considerably varied. However,it is an essential feature of the invention that the electric circuitshall be so arranged that the current will necessarily enter the waterin the boiler to one electrode, pass through the water to an adjacentelectrode in order that the resistance to the flow of current throughthe water be utilized to effect a heating action. Inasmuch as relativelyWide areas of adjacent electrodes are involved, it is obvious thatelectric currents of relatively heavy strength can be handled to therebyobtain rapid heating effects. In fact, the operation of this generatoris substantially instantaneous and is effective to raise the temperatureof the feed water to any desired temperature of water or to producetherefrom wet or superheated steam as desired in a relatively shorttime.

7 It will be readily understood that the electric current flowingthrough the device may be controlled by the usual types of electricalcontrol means such as rheostats or adjustable transformers in order tovary the heating effect of this device as desired and such controls canalso be readily operatively connected to various conditions of theapparatuses to which the heated water or steam is to be supplied inorder to through such conditions control the generation of steam by thisgenerator.

The manual adjustment of the spacing of the electrodes can be effectedin a number and variety of ways. One convenient manner is that shown inFIGURES 2, 3 and 5, and may consist of a mounting bracket as at 90 whichis secured to the top cover 38 of the boiler as by one of the fasteningbolts 36, and which has an upstanding apentured projection 92 which isdisposed adjacent the end of the enlarged portion 78 of the dielectricbody. Secured in this aperture against axial displacement but rotatabletherein is a thumb screw 94 having an externally threaded stem 96 whichis received in an internally threaded bore 98 formed in the end of thedielectric body 78. The arrangement is such that as the thumb screw 94is rotated, and is held against axial displacement by the arm 92 ofbracket 90, it will in turn impart a longitudinal pushing or pullingmotion to the dielectric body and through the connection of thebifurcated arm 76 thereof with the crank arm 74 of the electrodes, willeffect a rotation of the electrodes in unison.

It will be understood that in place of the thumb screw means such poweroperating means as solenoids, devices responsive to fluid pressure suchas water pressure, steam pressure and the like, thermostatic controls,or a combination of the same may be utilized to eifect the rotationaladjustment of the electrodes for the purpose of varying the rate of heatinput into the boiler.

Referring now more specifically to the arrangement shown in FIGURE 1, itis to be here noted that the bypass line 22 is provided with a checkvalve 24. This valve may be of any conventional design but is of thetype preferably which will open and permit the flow of fluid from theinterior of the boiler downwardly therefrom and into the supply line 12through a fitting 100'. The check valve is preferably of the pressurerelief type and is also preferably capable of being adjusted to regulatethe pressure at which the valve will open and permit the escape of fluidfrom the tank. Inasmuch as valves of this character are well known inthemselves, and the principles of the invention are not limited to theparticular details of any valve of such type, a further description ofthe same is deemed to be unnecessary.

In operation, the valve 24 will be set to open at a predeterminedpressure which it is desired to maintain in the boiler. When thispressure is exceeded as by reason of the generation of steam in theboiler which thus rapidly increases the pressure therein, the valve willopen and permit the escape of fluid from the bottom of the boiler, thisfluid being discharged into the supply line 12, the reservoir tank 16provides means to receive this fluid which displaces any fluid alreadyin the tank and forces it down line '12 in opposition to the pressuretherein. Thus, by continuing to supply heat to the boiler and thusgenerating steam in the boiler faster than the same is to be withdrawnunder the controls imposed upon the delivery conduit 18, the pressuretherein will rise and this pressure increase will eject water from thelower end of the boiler as just mentioned. Thus, by this con trolledejection of water, the liquid level in the boiler can be caused to dropto a lower level such as that shown at 102 which will thus result insteam being present above this level in the boiler while heated waterwill lie below this level. It is evident that the lowering of the levelwill reduce the total area of the electrode plates which are exposed orimmersed in the liquid and therefore decrease the surfaces from whichthe electric current is flowing to thereby in turn diminish the heatingcapacity of the system.

Still further, this operation can be controlled and continued until theliquid level passes entirely beneath the electrodes, or until the boileris entirely filled with steam if desired. Under this condition theheating effect can be employed to produce a superheated dry steam, orsteam of varying degrees of wetness in order to adapt the device tosupply steam to apparatuses in accordance with their specificrequirements. It will be observed that the heated liquid thus ejectedfrom the boiler is not wasted but is temporarily stored in reservoir '16for future use. Without reservoir 16, the hot water would be forced intothe length of pipe 12 and thereby rapidly cooled.

The present invention also includes the provision of means foreconomizing on the use of the steam delivered by the line 18. When suchsteam has served its desired function in the apparatus to which it isdischarged, it may be reclaimed in any suitable manner, condensed, andthe condensed water therefrom returned by condensate return line 104into the feed line 12. For this purpose there is provided a fitting 106which preferably is of a venturi nature so that the flow of feed watertherethrough under the control of valve 14 will inspirate or draw in thewater condensate to the line 104 thus returning this into the boiler.The fitting 106 comprises a conventional venturi sleeve and has atapered passage therethrough which is restricted at its center andenlarged at its ends. The center of the venturi sleeve comprises thethroat of the venturi. The velocity of the fluid through the center ofthe venturi passage being relatively great causes the pressure to dropthereby drawing fluid from line 164. This effects a great economy in theuse of Water by the device as well as an economy in the heat requiredfor the operation of the apparatus.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. An electrical steam generator comprising a boiler closed from theatmosphere, means for supplying water into said boiler for heating,means for discharging steam or heated water from said boiler, animmersion heater in said boiler, said heater comprising a plurality ofelongated electrodes disposed in side-by-side spaced relation andimmersed in said water whereby to heat said water upon flow of electriccurrent between said electrodes and through said water, each of saidelectrodes pivotally mounted in said boiler on a Longitudinal axis, allof the Mes being parallel and coplanar, means for supplying an electriccurrent to said electrodes, operating means connected to said electrodesso as to simultaneously vary the distance between said electrodes, atpressure responsive fluid discharge means communicating with the lowerporaicgaos tion of said boiler and a reservoir chamber for receiving andstoring the hot water discharged from said boiler by steam pressuretherein, said reservoir beingdirectly below saidbtoiler and connectedthereto by a short conduit including said'pressure responsive fluiddischarge means. 1

2. Anelectrical steam generator comprising a boiler closed from theatmosphere, means for supplying water into said boiler for heating,means for discharging steam or heated water from said boiler, animmersion heater in saidgboiler, said heater comprising a plurality ofelongated electrodes disposed in side-by-side spaced relation andimmersed in said water whereby to heat said. water upon flow of electriccurrent between said: electrodes and through said water, each of saidelectrodes pivotally mounted in said boiler on a longitudinal axis, allof the axes being parallel and coplanar, means for supplying an electriccurrent to said electrodes,.operating means connected to said electrodesso as to simultaneously vary the distance between said electrodes, saidelectrodescomprising flat plates, insulating means journaling and sup:

porting said plates at opposite ends for rotation about the longitudinalaxes, said axes disposed in side-by-side relation whereby to vary thedistance between adjacent surfaces of adjacent plates, each plate havingan axle concentric with'the axes, at least one of said axles extendingthrough a wall of saidboiler to the exterior thereof, said operatingmeans being connected to said extending axle. 3; An electrical steamgenerator comprising a boiler closed from the atmosphere, means forsupplying water into said boiler for heating, means for dischargingsteam electric current to said electrodes, operating means connectedtosaid electrodes so as to simultaneously vary the distance between saidelectrodes, a fluid discharge means communicating with the lower portionof said boil-er for regulating the level and pressure of liquid in saidboiler and thereby regulating, the area of the electrodes submerged insaid liquid and which isefiective as aheating agent, said fluiddischarge means including a non-return pressure relief check valveallowing escape offluid from said boiler at a predetermined pressuretherein whereby increase in steam pressure in said'boiler above saidpredetermined pressure will discharge fluid and lower the liquid levelin the boiler, saidfiuid discharge means delivers into said-supplymeans, a reservoir tank communicating with said supply means via saidcheck valve.

4. An electrical steam generator comprising a'boiler closed from theatmosphere, means for supplying water 8;- into said boiler for heating,means for discharging steam or heated Water from said boiler, animmersion heater in said boiler, said heater comprising a pluralityofelongated electrodes disposed in side-by-side spaced relation andimmersed in said water whereby to heat said water. upon flow of electriccurrent between said electrodes and through said water, each of saidelectrodes pivotally 'mounted in said boiler on a longitudinal axis, allof the axes being parallel and coplanar, means for supplying an electriccurrent to said electrodes, operating means connected to said electrodesso as to simultaneously vary the. distance between said electrodes, saidoperatingmeans including an axle connectedito each electrode and havingone end extending through a wall portion of the boiler, a lever exteriorof said boiler fixed to saidone end of ;each axle, rigid means pivotallyconnecting each lever whereby all [the levers and: electrodes may bepivoted simultaneously.

5. A device as defined, in claim 4 wherein each lever is parallel to theother levers, said rigid means comprises a plate pivotally connected toa free end of each lever, an operating knob rotatably mounted on theexterior of said boiler and fixed against axial movement, screw meansoper-atively connecting said knob and plate.

6. An electrical steam generator comprising a boiler closed from theatmosphere, means for supplying water into'said boiler for heating,means for discharging steam or heated water from said boiler, animmersion heater in said boiler, said heater comprising a plurality ofelongated .electrodes disposed in side-by-side spaced relation andimmersed in said water whereby to heat said water upon flow of electriccurrent between'saidelectrodes and through said water, each of saidelectrodes pivotally mounted in said boiler on a longitudinal axis, allof the axes being parallel and coplanar, means for supplying an electriccurrent to said electrodes, operating means connected to said electrodesso as to simultaneously vary the distance between said electrodes, saidmeans for supplying water including a conventional. venturi connected atits throat to a condensate return line. so as tosiph0n fluid therefrom.

References Cited in the file of this patent I V 'UNITED STATES PATENTS-Abogado June 21, 1921 1,450,833 Bergeon Apra3, 1-923 1,526,014Russell'etal Feb: 1-0, 1925 1,680,397 Stransky Aug. 14', 1928 1,742,406Mascarini Jan. 7, 1930 1,949,086 Smith Feb. 27,1934

FOREIGN PATENTS 92,636 Switzerland Jan. 16; 1922 242,118 SwitzerlandSept. 16; 1946 659,352

Great Britain Oct; 24,1951

2. AN ELECTRICAL STEAM GENERATOR COMPRISING A BOILER CLOSED FROM THEATMOSPHERE, MEANS FOR SUPPLYING WATER INTO SAID BOILER FOR HEATING,MEANS FOR DISCHARGING STEAM OR HEATED WATER FROM SAID BOILER, ANIMMERSION HEATER IN SAID BOILER, SAID HEATER COMPRISING A PLURALITY OFELONGATED ELECTRODES DISPOSED IN SIDE-BY-SIDE SPACED RELATION ANDIMMERSED IN SAID WATER WHEREBY TO HEAT SAID WATER UPON FLOW OF ELECTRICCURRENT BETWEEN SAID ELECTRODES AND THROUGH SAID WATER, EACH OF SAIDELECTRODES PIVOTALLY MOUNTED IN SAID BOILER ON A LONGITUDINAL AXIS, ALLOF THE AXES BEING PARALLEL AND COPLANAR, MEANS FOR SUPPLYING AN ELECTRICCURRENT TO SAID ELECTRODES, OPERATING MEANS CONNECTED TO SAID ELECTRODESSO AS TO SIMULTANEOUSLY VARY THE DISTANCE BETWEEN SAID ELECTRODES, SAIDELECTRODES COMPRISING FLAT PLATES, INSULATING MEANS JOURNALING ANDSUPPORTING SAID PLATES AT OPPOSITE ENDS FOR ROTATION ABOUT THELONGITUDINAL AXES, SAID AXES DISPOSED IN SIDE-BY-SIDE RELATION WHEREBYTO VARY THE DISTANCE BETWEEN ADJACENT SURFACES OF ADJACENT PLATES, EACHPLATE HAVING AN AXLE CONCENTRIC WITH THE AXES, AT LEAST ONE OF SAIDAXLES EXTENDING THROUGH A WALL OF SAID BOILER TO THE EXTERIOR THEREOF,SAID OPERATING MEANS BEING CONNECTED TO SAID EXTENDING AXLE.